Horizontal extrusion of edge rippled snack product

ABSTRACT

A dough strip extruder, such as a lasagna noodle extruder, for extruding one or more ripple edge strips is oriented to extrude the strips horizontally. The extruded strips are supported as they leave the extruder to maintain the strips in the horizontal plane of the extrusion passageway for a distance sufficient to allow complete formation of the undulations on the edges. The support may be by a roller, cylindrical rod, or horizontal plate.

This is a continuation of application Ser. No. 07/942,441, filed Sep. 9,1992, now abandoned, which is a divisional of Ser. No. 07/690,666, nowU.S. Pat. No. 5,167,980, filed Apr. 24, 1991.

TECHNICAL FIELD

The invention relates to methods and apparatus for the extrusion ofstrip food products which have undulating or rippled edges, andparticularly to extrusion in a horizontal plane.

BACKGROUND ART

Extrusion of food strip products with undulating edges, such as lasagnanoodles, is performed by dies which have strip extruding passagewaysdesigned to extrude the edge portions of the strips at a greatervelocity than the central portions of the strips so that the edgesundulate. Generally the greater velocity of the edge portions isproduced by contouring the passageways to have reduced resistance to theflow of the dough at the edges of the passageways.

One type of prior art lasagna extrusion passageway has an elongatednarrow orifice which includes a rectangular central portion of a firstwidth, end rectangular portions of a second width which is less than thefirst width, and terminating circular portions of a diameter slightlylarger than the second width. The larger central portion of theextrusion passageway extends substantially through the die. Largediameter bores extend from the rear of the die and the edge portions ofthe extrusion passageway open into these bores to substantially reducethe length of the edge portions of the extrusion passageway. The reducedlength of these edge portions results in reduced resistance to flow ofthe dough to produce the undulation of the edges of the strip of doughas it is extruded. The circular terminating portions of the die slitprovide reduced flow resistance to compensate for edge resistance whichotherwise could produce tearing or non-uniform flow of the edges of theextruded strip.

Prior art lasagna extrusion dies have their extrusion passagewaysextending downward in a vertical plane so that the lasagna strips areextruded downward in the vertical plane. The extrusion velocity isrelatively slow and the lasagna noodles are severed by a cutting toolmoving across the face of the extrusion die.

In the manufacture of salty segmented strip snack products such as snackchips, a higher rate of extrusion, compared to lasagna noodle extrusion,is desirable to make practical quantities of product. At such higherrates of extrusion, cutting the segments by wiping a cutting tool acrossthe face of the die is impractical since the segments are distorted bythe cutting tool. Extruding and cutting the strip dough products on ahorizontal conveyor avoids the distortion of the snack segments. Whenhorizontal extrusion of edge undulating strips is attempted, theundulations are highly irregular, and randomly spaced.

SUMMARY OF INVENTION

The present invention is summarized in a method and apparatus forproducing strips of food product with undulating edges, wherein a stripof dough is extruded horizontally from an edge-ripple-forming extrusiondie, and the extruded strip is supported adjacent the extrusion die sothat the undulating edges are formed with a steady frequency.

An object of the invention is to enable the horizontal extrusion of edgerippled dough strips.

Another object of the invention is to eliminate irregularity in the edgeundulations of a dough strip extruded horizontally from a ripple-formingdie.

One advantage of the invention is that segmented snack strips withrippled edges can be produced using conventional horizontal processingequipment.

A feature of the invention is the discovery that the irregularity inundulations formed on the strip edges of a horizontally extruded stripcan be eliminated by maintaining the extruded strip in the horizontalplane of extrusion for a short distance in front of the extruding die.

Other objects, advantages and features of the invention will be apparentfrom the following description of the preferred embodiments taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is top plan view of a broken away portion of an apparatus forproducing segmented strip snacks in accordance with the invention.

FIG. 2 is a side elevation view of the apparatus of FIG. 1.

FIG. 3 is an enlarged side elevation view of a broken away portion of ahorizontally oriented prior art extrusion apparatus attempting toextrude strips with rippled edges.

FIG. 4 is a view similar to FIG. 3 but of the apparatus of FIGS. 1 and2.

FIG. 5 is a front elevation of an extrusion die broken away from theapparatus of FIGS. 1 and 2.

FIG. 6 is an enlarged front elevation view of a broken away portion ofan extrusion die insert of FIG. 5 showing a single extrusion orifice.

FIG. 7 is a horizontal section view taken at dotted line 7--7 in FIG. 6.

FIG. 8 is a perspective view of a broken away segment of a dough stripextruded by the apparatus of FIGS. 1 and 2.

FIG. 9 is a rear view of a modified portion of an apparatus forproducing segmented strip snacks in accordance with the invention.

FIG. 10 is a side elevation view of a support portion of the apparatusof FIG. 9.

FIG. 11 is a front elevational view of a portion of another variation ofthe apparatus for producing segmented strip snacks in accordance withthe invention.

FIG. 12 is a side elevation view of still another variation of theapparatus for producing segmented strip snacks in accordance with theinvention.

FIG. 13 is cross-sectional front elevation view of another modifiedsupport mechanism for extruding a plurality of edge undulated strips.

FIG. 14 is a side elevational view of a further variation of theapparatus for producing segmented strip snacks in accordance with theinvention.

FIG. 15 is a side elevational view of a still further variation of theapparatus for producing segmented strip snacks in accordance with theinvention.

FIG. 16 is a cross-sectional view of a modified roller configuration forsupporting a horizontally extruded dough strip.

FIG. 17 is a cross-sectional view of a another modified rollerconfiguration for supporting a horizontally extruded dough strip.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIGS. 1 and 2, one embodiment of the invention utilizes ahorizontally oriented dough strip extrusion mechanism indicatedgenerally at 20 together with a strip support mechanism indicatedgenerally at 22 for supporting a plurality of dough strips 24 in ahorizontal plane as the strips are being extruded from the extrusionmechanism 20. The strips 24 are maintained in this horizontal plane fora selected distance until undulations are fully formed on the edges ofthe strips. It has been discovered that the maintenance of the extrudingstrips in a horizontal plane results in uniform undulations on the edgesof the strips.

The strips 24 are fed by a conveyor 26 to a cutter 28 which cuts thestrips into segments 30. Subsequently these severed segments 30 arepassed to conventional snack chip processing equipment such as a fryer(not shown) where the segments are cooked, a seasoning mechanism (notshown) where the cooked segments are seasoned such as salted, andpackaging mechanism (not shown) where the seasoned segments are packagedfor shipment and sale to consumers.

As illustrated in FIG. 8, each of the strips 24 has a flat centralportion 32 and edges with undulations 34. The undulations aresubstantially uniform in amplitude (height above the plane of thecentral portion 32) and periodicity (spacing between undulations). Thisresults in a pleasing and attractive snack chip. These chips can be madefrom a variety of flours such as wheat flours, corn flours, etc.

The extrusion mechanism 20 includes a die or extrusion distribution head35 on which is secured a die plate 36 containing a die insert 38 havinga plurality of slit-like orifices 40, FIG. 5, from which the doughstrips are extruded. Alternatively there are a plurality of die inserts(not shown) each containing one or more die orifices. The die insert orinserts are formed by conventional techniques such as machining of splithalves (not shown). The die insert 38 of FIGS. 1 and 5 is shown ashaving six extrusion orifices 40; however any number of orifices, forexample nine, can be formed in the insert or inserts of an extrusionapparatus.

Each orifice 40, as illustrated in FIG. 6, has a central horizontallyelongated rectangular portion 42 of width 44 and edge horizontallyelongated rectangular portions 46 of width 48. The width 48 is less thanthe width 44. At the extreme edges, the orifices 40 terminate incircular portions 50 which have a diameter slightly larger than thewidth of the portions 46. An extrusion passageway 52, FIG. 7, extendsthrough the die insert 38 along a horizontal plane as represented bydotted line 7--7 in FIG. 6 and communicates with the distributionpassage or passages (not shown) in the die head 35. In the front portionof the die insert 38, the extrusion passageway 52 has the same crosssection as the orifice 40. The cross section of the central portion 42extends through the die insert or at least a substantial portionthereof. However the narrower edge portions 46 and circular portions 50open into large diameter horizontal bores 54 formed in the rear of thedie insert.

Since resistance to the flow of the dough in a passageway is dependentupon the length of the passageway as well as the cross-sectional area ofthe passageway, the outer edges 46 of the passageway 52 have lessresistance than the central portion 42. This results in the doughextruding from the edges 46 of the orifice at a faster velocity than thevelocity of extrusion from the central portion 42. The circular portions50 provide a reduction in flow resistance to compensate for edge wallresistance to the flow.

The flow of the dough through the orifice is also a function of therheological properties of the dough. Generally the preferred rheologicalproperties of the dough are derived empirically. The rheologicalproperties of the dough used for production of segmented snack chips arecontrolled to produce product with uniform edge undulations.

The ripple or wave shape of each edge portion has an amplitude 56, FIG.4, (height above the plane of the central portion 32) and a pitch 58(longitudinal distance from one peak to the next peak) each determinedby the periodicity or frequency of ripple formation and the ratio of thevelocities of the center and edge portions of the strip. Assuming eachwave's maximum distance to the right or left of the central mass can beapproximated by the shape of a triangle, ##EQU1## where a is theamplitude 56, P is the pitch 58, S1 is extrusion velocity of the centralportion 32, and S2 is the extrusion velocity of the strip edge portions.Similarly, the differential velocity, S2/S1, can be estimated by theequation ##EQU2## when the amplitude and pitch are known. The pitchdistance is smaller and/or the corresponding amplitude is larger whenthe edge/center speed ratio is higher.

The detailed configuration of the extrusion passageways in theabove-described extrusion die, except for the horizontal orientation, issimilar to conventional vertically oriented lasagna noodle extrusiondies. Also there exist several other conventional vertical lasagnanoodle extrusion passageway configurations (not shown) which can beoriented horizontally and substituted for the described extrusion die.

When the die is used to horizontally extrude a strip 60 as shown in FIG.3, the strip has a tendency to fall under the force of gravity toproduce a downward curved strip from the die orifice. The greatervelocity of the flow of the edge portions of the extruded strip resultsin a length on the edge which is greater than the length of the centralportion of the strip. In normal downward extrusion of lasagna strips,the extra edge length is taken up by the undulations of the edges. Wherethe strip curves downward from the orifice of the die as shown in FIG.3, a substantial portion of the extra length in the strip edges is takenup by a larger downward radius of curvature as shown by dashed line 62.This results in the strip edges having large generally one-sided rippleswhich occur irregularly. For extrusion where the difference between theouter edge velocity and the inner central portion velocity is reduced,all of the extra length can be taken up by the larger circular path ofthe outer edges to completely eliminate the undulations.

In contrast as shown in FIG. 4, cylindrical member 66 supports the strip24 in front of the die so that the strip is extruded in a horizontalplane until the ripples 34 are fully formed. Thereafter, the ripples 34retain their regularity even when the strip 24 is bent through asubstantial downward curvature. Generally when only a single bar orroller is employed, the distance 64 of the member 66 from the face ofthe die is at least equal to or greater than one-half of the period 58.Preferably the distance 64 is two times the period 58 or more. Forexample the distance 64 can be in the range from 25 to 51 mm (1 to 2inches).

Referring back to FIGS. 1 and 2, the cylindrical support member may bein the form of a stainless steel or polytetrafluoroethylene roller 68which has a low coefficient of friction. Axles 70 protruding axiallyfrom ends of the roller 68 are journaled in circular openings of arms 72and 74. These arms are mounted by wing nuts 76 on studs or bolts 78extending from opposite sides of the extrusion mechanism 20.Conveniently the arms 72 and 74 have slotted openings 80 enablingadjustment of the spacing between the roller 68 and the front of the die20. The vertical position of the roller 68 can also be adjusted bypivoting the arms 72 and 74 about the bolts 78.

The employment of a roller or rollers for maintaining the extruded stripor strips in a horizontal plane immediately after extrusion has anadvantage over a bar or plate in that the rotation of the roller tendsto reduce product deformation that would be caused by adherence orsliding friction of the dough strip to a stationary and non-rotatingsupport member.

A modification of the mounting structure for the roller 68 is shown inFIGS. 9 and 10 wherein the arms 72 and 74 are attached by wingnuts 82and bolts 84 to the ends of respective arms 86 and 88. These arms havetheir opposite ends slotted to fit on a bar 90 which is mounted over theend of the conveyor 26. Thumb screws 92 on the slotted ends adjustablysecure the arms 86 and 88 on the bar 90.

A variation of the apparatus for horizontally extruding a ripple edgestrip of dough is generally shown at 100 in FIG. 11. The extrusion dieinsert 102 contains a single rectangular extrusion slot 104 forextruding a strip in a horizontal plane. The extrusion passageway hasconventional facilities (not shown) for forming rippled edges on thestrip being extruded. The cylindrical support member of this variationis in the form of a metal rod 106. This rod is adjustably supported by abeaker clamp 108 on a rod 109 connected by dual clamp 110 to rod 112which is mounted by beaker clamp 114 on the stem of pressure gauge 116of the extrusion mechanism.

In still a further variation shown in FIG. 12, a horizontal rippled edgedough strip extruder insert die 120 has a horizontal plate 122 mounted,such as by welding, on its face below the orifice of die passageway 124.The distance of the plate below the die orifice is equal to the desiredripple amplitude. The plate 122 extends horizontally from the die faceby at least one-half of the undulation pitch distance and preferably inthe range from 0.5 to 2.0 times the pitch distance before runningdownward in the curved edge 126.

A modification of the support mechanism for supporting a plurality ofdough strips in a horizontal plane is illustrated in FIG. 13. Instead ofa single roller each strip, or the central portion thereof, of aplurality of strips 24 is supported by an individual roller 130 mountedon an arm 132 which can be adjusted in a manner similar to that of FIG.10.

In another modification of the support mechanism shown in FIG. 14, aseries of rollers 136 or rods (not shown) support the strip beingextruded. The rollers 136 are closely spaced, one after the other, fromthe die orifice through a distance insuring additional support for lowviscosity materials until the undulations become set.

In FIG. 15, the cutter conveyor 26 is positioned close to the extrusionorifice(s) so that its extrusion receiving end supports the extrudingstrip(s) in a horizontal plane until the undulations become set.

As illustrated in FIGS. 16 and 17, the supporting roller or rollers canhave polygonal cross-sectional configurations. The cross section of theroller 140 of FIG. 16 is octagonal while the cross section of roller 142of FIG. 17 is decagonal.

EXAMPLE

A single orifice die in an extrusion apparatus similar to that shown inFIG. 11 had an extrusion passageway similar to that shown in FIGS. 6 and7. The width 44 of the central portion of the die orifice was 0.53 mm(0.023 inches) and the width 48 of the edge portions of the die orificewas 0.53 mm (0.021 inches). The diameter of the circular terminatingportions was 0.74 mm (0.029 inches). The total length of the die orificewas 24.56 mm (0.967 inches), the length of the central portion 42 was18.24 mm (0.967 inches), and the length of each edge portion was 2.79 mm(0.110 inches). The bores 54 had a diameter of 6.35 mm (0.250 inches)and extended into the back of the die leaving a horizontal run of about11.13 mm (0.438 inches) for the edge portions 46 of the die passageway.The central portion 42 of the die passageway ran from the rear to thefront for a distance of 12.7 mm (0.5 inches). The bar 106 was adjustedduring the initial production run to be placed approximately 25.4 mm(one inch) in front of the die with its upper edge just below theorifice so that the extruding strip lies substantially in a horizontalplane from the orifice to the bar. A dough formed from semolina #2 (finesemolina) was extruded through the extrusion apparatus, cut intosegments, and then fried for 25 seconds. The product chips had evenregular ripples on the side edges.

Since many modifications, variations and changes in detail can be madeto the described embodiments, it is intended that the foregoingdescription be interpreted only as illustrative of examples of theinvention, and that many other embodiments can be constructed withoutdeparting from the scope and spirit of the invention.

What is claimed is:
 1. An apparatus for producing strips of food productwith regular, evenly-formed undulating edges, comprising:an extrusiondie having means for horizontally extruding a strip of dough, the stripof dough having undulating edge portions on opposite lateral edges of asubstantially horizontal central portion upon said strip exiting theextrusion die; ripple supporting means for supporting the strip ofextruded dough after the strip exits the extrusion die for a distancethat is sufficient to permit the undulating edge portions of said doughstrip to be fully formed so as to produce regular evenly-spacedundulating edge portions in the strip of dough.
 2. An apparatusaccording to claim 1 wherein the extruding means comprises a passageextending along a horizontal plane and exiting in an elongatedsubstantially horizontal opening from which the strip is extruded.
 3. Anapparatus according to claim 2 further comprising means for adjustingthe relative position of the ripple supporting means with respect to theopening of the extrusion die.
 4. An apparatus according to claim 1wherein the ripple supporting means comprises a cylindrical member andmeans for supporting the cylindrical member with its axis disposedhorizontally and transversely to the strip of extruded dough.
 5. Anapparatus according to claim 4 wherein the cylindrical member is aroller.
 6. An apparatus according to claim 4 wherein the cylindricalmember is formed of a material having a low coefficient of friction. 7.An apparatus according to claim 4 wherein the cylindrical member is arod.
 8. An apparatus according to claim 1 wherein the ripple supportingmeans includes a roller having a polygonal cross section and means forsupporting the roller with its axis disposed horizontally andtransversely to the strip of extruded dough.
 9. An apparatus accordingto claim 2 wherein the ripple supporting means includes a cylindricalmember disposed in the range from about 1 to 2 inches from the dieopening, and means for supporting the member with its axis disposedhorizontally and transversely to the strip of extruded dough.
 10. Anapparatus according to claim 1 wherein the ripple supporting meanscomprises a plate member disposed beneath the extruding strip, the platemember comprising a curved edge located on a downstream end of the platemember in an extrusion direction of the extruding strip.